Various power converters have been widely used to provide regulated output voltage and current. Typically, the power converters have a transformer that isolates the input and output terminals of the power converter for safety and reliability reasons. The input terminals at a primary-side can receive electrical power such that the transformer can pass the electrical power to the output terminals at a secondary-side. Most power converters use a switch to switch the electrical power through the transformer. In prior power converters, a controller controls the switch based on a feedback voltage signal from an optical-coupler coupled with an output voltage of the power converter. These prior power converters also required a secondary-side regulator to regulate the output voltage and current at the secondary-side of the power converter. A disadvantage of these prior power converters is that they required an optical-coupler and secondary-side regulator, thereby increasing the size and costs for the power converters.
Furthermore, in prior power converters, the switching of the electrical power through the transformer can cause electrical spikes and electromagnetic interference (EMI) in the power converters. Such prior power converters provided poor protection from spikes and EMI. Thus, what is needed is reducing the size and costs of power converters, while providing protection against electrical spikes and EMI.